CD48 antigen (Cluster of Differentiation 48) is also known as B-lymphocyte activation marker (BLAST-1) or signaling lymphocytic activation molecule 2 (SLAMF2). CD48 is a member of the CD2 subfamily of the immunoglobulin superfamily (IgSF) which includes SLAM (signaling lymphocyte activation molecules) proteins, such as CD84, CD150, CD229 and CD244. CD48 is found on the surface of lymphocytes and other immune cells, and dendritic cells, and participates in activation and differentiation pathways in these cells. CD48 is known to be expressed on multiple myeloma cells and other cancers of B cell origin, e.g., non-Hodgkins lymphoma (NHL), Chronic lymphocytic leukemia (CLL), Monoclonal Gammopathy of Unknown Significance (MGUS), Waldenstrom's Macroglobulinemia (WM), Primary/Systemic Amyloidosis patient tumor cells, and follicular lymphoma (FL).